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86 | IV. Categories of animal associations
and a host of obstant elements (Eupelmus [Eupelmella], Pteromalus
[Habrocytus], Phaenecra). On the underside of the leaves, Doralitena fabae
appear and are active until mid-summer, bringing several obstant elements
into the poppy field (Syrphus, Chrysopa, Aphidius, Coccinella, Pachyneuron,
Coruna [Pachycrepis] etc.). In the bud stage, we find the Ceutorrhynchitena
maculae-albae, followed by Dasyneuraetena papaveris; both are sources of a
rich trophic chain (Bracon, Chelonus [Chelonella], Tetrastichus, Eurytoma,
Pediobius [Rhopalotus], etc.).
All these catenae, for the reason of a shared energy source, necessarily
belong together, and will form a bigger unit of animal association, here named
the catenarium, a chain of catenae.
The catenae of the catenarium are kept together by the common food plant
that also anchors them, even if temporarily, in an oecus. In this way, a quality
energy source will keep together animal associations that are characteristic,
at least to a certain degree. The catenae of the catenarium do not have as strong
interrelationships as the members of an individual catena, because between
them, apart from the common energy source and eventual multi-catenal
obstant and intercalary populations, they have scarcely any horizontal link.
Without doubt, such catenaria exist. The catenae of the poppy field listed
above are entirely different than the population groups of Oscinellaetena frit,
Chloropiditena pumilionis and Cephitena pygmaei living in a wheat field. The
catenaria of an oecus composed of oak or beech trees will be sharply different,
as will be the catenaria of rose or hazelnut bushes.
Although the catenae forming a catenarium are independent, there is no
doubt that their living side-by-side will, inevitably, stimulate interactions
that will influence their development, population dynamics, and trophic
needs. The interrelationships that are a criterion of all animal associations,
therefore, doubtlessly exist in the catenarium. The intercalary elements living
on animal debris will not join a single catena in such high numbers compared
to a catenarium where there is much more debris, and of more varied quality.
The activity of corrumpent elements can cause the death of plant parts,
allowing the assimilation of syrmatophagous elements. The sustinents, by
their nature, are temporary elements of any catenarium where the food plant
requires insect pollination. The possible insertion of corrumpent elements
that live on seeds or fruit also depends on their activity, as well as of the
relevant catenae, but all these can be blocked by the activity of corrumpents
specialised on flower buds. Ifthe Contarinia medicaginis uses the flower buds
of the lucerne, the sustinents will be absent from the oecus, and neither the
Tychiitena flavi nor the Bruchopagitena gibbi can develop there. A single
catena within a catenarium can, therefore, influence the density of certain
population groups in the same way as within a catena; a given trophic level
can influence the one below or above it.
The catenarium will directly connect with the plant cover in all directions
(through all catenae). A carcass therefore cannot be a catenarium, whose